Valve and manufacturing method thereof

Abstract

The invention provides a valve and a manufacturing method thereof, the valve comprises a valve body, a prefabricated ring and a valve core, the inner wall of the prefabricated ring is provided with a sealing surface abutting against an abutting surface on the valve core, and the valve core can abut against the sealing surface of the prefabricated ring to realize sealing of the interior of the valve body. The sealing surface is formed on the prefabricated ring, and the assembly of the prefabricated ring in the accommodating position in the valve body is realized in an electron beam welding manner, so that the problem that a welding gun cannot enter an internal space with a smaller size for surfacing and cannot form the sealing surface with reliable quality can be effectively solved; therefore, the sealing surface of the valve can meet the requirements of higher hardness and wear resistance, and the overall stability and reliability of the valve are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of valve and metal structural part processing, and in particular to a valve and a manufacturing method thereof. Background Art

[0002] In order to ensure the quality and service life of the valve, the industry has high requirements on the hardness and wear resistance of the valve sealing surface.

[0003] At present, the common practice is to cast the valve body with conventional materials and then weld a layer of hard alloy on the sealing surface to meet the above requirements. For valves with larger nominal diameters, conventional methods such as automatic argon arc welding, metal arc welding, and arc welding can be used to weld the sealing surface. After the welding is completed, machining is performed to produce a sealing surface that meets the requirements.

[0004] However, for valves with smaller nominal diameters, especially those with sealing surfaces less than DN40, apertures less than 30mm, and depths greater than 50mm, the welding gun cannot enter the interior for welding due to the size limitations of the welding equipment. Even if it can barely penetrate deep enough, it is impossible to operate the welding gun and observe the operation process, and a reliable quality cemented carbide welding surface cannot be effectively formed. This will result in the valve sealing surface being unable to meet the higher hardness and wear resistance requirements, and the overall reliability of the valve is poor. Summary of the invention

[0005] The purpose of the present invention is to solve the technical problem in the prior art that, for valves with smaller nominal diameters, due to size limitations, it is impossible to form a reliable quality cemented carbide cladding surface, resulting in the valve sealing surface being unable to meet the requirements of higher hardness and wear resistance and the overall reliability of the valve being poor.

[0006] In order to solve the above technical problems, the present invention provides a method for manufacturing a valve, which comprises the following steps: Processing the valve body, forming a connected inlet and outlet on the valve body, and forming a receiving position inside the valve body; Processing a prefabricated ring, the size of which can be adapted to the size of the accommodation position, assembling the prefabricated ring to the accommodation position, so that the valve body and the prefabricated ring form an assembly structure; The assembly structure is welded by electron beam welding so that the outer wall of the prefabricated ring is welded and fixed to the inner wall of the valve body corresponding to the accommodation position; A sealing surface is then processed on the inner wall of the prefabricated ring, and the sealing surface can abut against the abutting surface at the end of the valve core to form a seal.

[0007] In some embodiments of the present application, the accommodating position is a groove-shaped structure, and the depth of the accommodating position is not less than 4 mm; the inner diameter of the accommodating position is a negative tolerance, and the tolerance range is -0.05 mm-0 mm.

[0008] In some embodiments of the present application, the prefabricated ring is made of cemented carbide powder by casting, and the cemented carbide powder is a cobalt-based alloy; In terms of weight percentage, the cobalt-based alloy includes the following components: Co: 44.5%-65.1%, C: 0.9%-1.4%, Cr: 28%-30%, Fe: 0.8%-3%, Mo: 0.2%-1%, Ni: 0.8%-3%, Si: 0.7%-1.55%, W: 3.5%-5.5%; The outer diameter of the prefabricated ring has a positive tolerance, and the tolerance range is 0mm-0.05mm.

[0009] In some embodiments of the present application, after the processing of the prefabricated ring is completed, before the prefabricated ring is assembled with the valve body, the prefabricated ring is first frozen, and then the frozen prefabricated ring is assembled to the accommodating position to create an interference fit between the prefabricated ring and the valve body.

[0010] In some embodiments of the present application, before the assembly structure is welded by electron beam welding, the assembly structure is first placed in a vacuum chamber for vacuum treatment so that the vacuum degree is no greater than 0.01Pa.

[0011] In some embodiments of the present application, the thickness of the prefabricated ring at the sealing surface is not less than 1 mm, and the hardness of the prefabricated ring at the sealing surface is 38HRC-45HRC.

[0012] The present invention further provides a valve, which is manufactured by the above manufacturing method, and comprises: A valve body is provided with an inlet and an outlet connected to each other, and a receiving position is provided inside the valve body; A prefabricated ring, arranged in the accommodation position, wherein the inner wall of the prefabricated ring is formed with a sealing surface; The valve core is movably arranged on the valve body, and the end of the valve core can extend into the interior of the valve body, and the end of the valve core is formed with an abutment surface; the valve core moves relative to the valve body so that the end of the valve core can extend into the prefabricated ring and the abutment surface abuts against the sealing surface to form a seal.

[0013] In some embodiments of the present application, the sealing surface is an inclined surface, and in the direction in which the valve core extends into the valve body, the inner diameter of the prefabricated ring tends to gradually decrease; The abutting surface is an inclined surface, and in the direction in which the valve core extends into the valve body, the outer diameter of the end portion of the valve core where the abutting surface is formed tends to gradually decrease.

[0014] In some embodiments of the present application, the prefabricated ring includes a ring base and a ring body that are both annular and connected, and the outer surfaces of the ring base and the ring body are flush; the inner wall of the ring body constitutes the sealing surface, and the inner wall of the ring base is set at an obtuse angle to the sealing surface.

[0015] In some embodiments of the present application, the accommodation position is a groove-shaped structure opened inside the valve body, and the outer wall of the prefabricated ring and the inner wall of the valve body corresponding to the accommodation position are welded and fixed by electron beam welding.

[0016] In some embodiments of the present application, the prefabricated ring is a prefabricated alloy part, and the prefabricated ring is cast from cemented carbide powder.

[0017] In some embodiments of the present application, the cemented carbide powder adopts a cobalt-based alloy, and the cobalt-based alloy includes the following components by weight percentage: Co: 44.5%-65.1%, C: 0.9%-1.4%, Cr: 28%-30%, Fe: 0.8%-3%, Mo: 0.2%-1%, Ni: 0.8%-3%, Si: 0.7%-1.55%, and W: 3.5%-5.5%.

[0018] In some embodiments of the present application, the valve further includes a valve cover, which is arranged on the valve body and has a mounting hole; the valve core includes a valve stem and a valve flap connected to the end of the valve stem, and the end of the valve stem facing away from the valve flap is movably inserted into the mounting hole of the valve cover; the end surface of the valve flap away from the valve stem is formed with the abutment surface.

[0019] It can be seen from the above technical solution that the beneficial effects of the present invention are as follows: in the valve of the present invention and its manufacturing method, the valve includes a valve body, a prefabricated ring and a valve core, the inner wall of the prefabricated ring is formed with a sealing surface that abuts against the abutting surface on the valve core, and the valve core can abut against the sealing surface of the prefabricated ring to achieve sealing inside the valve body. The sealing surface is formed on the prefabricated ring, and the assembly of the prefabricated ring in the valve body is realized by electron beam welding, which can effectively solve the problem that the welding gun cannot enter the internal space of a smaller size for surfacing and cannot form a reliable quality sealing surface, thereby ensuring that the sealing surface of the valve can meet the requirements of higher hardness and wear resistance, and effectively improve the overall stability and reliability of the valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural cross-sectional view of an embodiment of a valve of the present invention.

[0021] Figure 2 It is a structural schematic diagram of a valve embodiment of the present invention.

[0022] Figure 3 It is a cross-sectional view of an embodiment of a valve of the present invention.

[0023] Figure 4 It is a flow chart of the steps of the manufacturing method of the valve of the present invention.

[0024] Figure 5 It is a schematic diagram of the welding operation of the prefabricated ring and the valve body during the manufacturing process of the valve of the present invention.

[0025] Figure 6 It is a schematic diagram of the connection structure after the prefabricated ring and the valve body are welded during the manufacturing process of the valve of the present invention.

[0026] The accompanying drawings are marked with numbers as follows: 100, valve; 10, valve body; 11, inlet; 12, outlet; 13, accommodation position; 14, circulation channel; 15, installation port; 16, installation channel; 20, prefabricated ring; 201, sealing surface; 21, ring base; 22, ring body; 30, valve core; 31, valve stem; 32, valve flap; 321, flap body; 322, abutment portion; 200, electron beam welding equipment; 300, electron beam. DETAILED DESCRIPTION

[0027] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations therein are essentially used for illustration purposes rather than for limiting the present invention.

[0028] In the description of the present application, it should be understood that in the embodiments shown in the drawings, the indications of directions or positional relationships (such as up, down, left, right, front and back, etc.) are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation. These descriptions are appropriate when these elements are in the positions shown in the drawings. If the descriptions of the positions of these elements change, the indications of these directions also change accordingly.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0030] See also Figures 1 to 3 An embodiment of the present application provides a valve 100 , which is manufactured by the manufacturing method of the present application. The valve 100 includes a valve body 10 , a prefabricated ring 20 and a valve core 30 .

[0031] Specifically, the valve body 10 is provided with an inlet 11 and an outlet 12 which are connected to each other, and a receiving position 13 is provided inside the valve body 10. A prefabricated ring 20 is arranged in the receiving position 13, and the prefabricated ring 20 is welded and fixed to the valve body 10, and a sealing surface 201 is formed on the inner wall of the prefabricated ring 20. The valve core 30 is movably arranged on the valve body 10, and the end of the valve core 30 can extend into the interior of the valve body 10, and an abutting surface is formed on the end of the valve core 30. The valve core 30 moves relative to the valve body 10, so that the end of the valve core 30 can extend into the prefabricated ring 20, and the abutting surface abuts against the sealing surface 201 to form a seal.

[0032] In one embodiment of the present application, a flow channel 14 is formed inside the valve body 10 for medium flow. An inlet 11 and an outlet 12 are also formed at both ends of the valve body 10 , and both the inlet 11 and the outlet 12 are connected to the flow channel 14 .

[0033] In some examples, a mounting port 15 is further provided on the side of the valve body 10 , and a mounting channel 16 is formed inside the valve body 10 corresponding to the mounting port 15 , and the mounting port 15 is communicated with the circulation channel 14 through the mounting channel 16 .

[0034] In some embodiments of the present application, the valve 100 may further include a valve cover, which is fixed to the installation opening 15 of the valve body 10 to close the installation opening 15. In some examples, the valve cover may be fixed to the valve body 10 by fasteners, which may be screws or pins.

[0035] Furthermore, the valve core 30 is disposed on the valve body 10 , and the valve core 30 can move relative to the valve body 10 , so that the end of the valve core 30 can extend into the circulation channel 14 , thereby controlling the on-off of the circulation channel 14 .

[0036] In some embodiments of the present application, the valve core 30 includes a valve stem 31 and a valve flap 32, and the valve flap 32 is connected to the end of the valve stem 31. The valve stem 31 can be connected to the valve body 10 through a valve cover, and the valve cover is provided with a mounting hole, and the mounting hole is used for connecting the valve stem 31 to the valve cover.

[0037] The mounting hole can be a blind hole or a through hole. The end of the valve stem 31 away from the valve flap 32 is inserted into the mounting hole, and the valve flap 32 is accommodated in the circulation channel 14. The valve stem 31 can move relative to the valve cover. Under the action of external force, the valve stem 31 can drive the valve flap 32 to rise and fall along the axis direction of the valve stem 31, thereby controlling the on-off of the circulation channel 14.

[0038] In some embodiments of the present application, the valve flap 32 may include a flap body 321 and an abutment portion 322 connected to the flap body 321, and the flap body 321 and the abutment portion 322 may be integrally formed. An assembly port may be provided on the end surface of the flap body 321, and the flap body 321 is sleeved on the end of the valve stem 31 through the assembly port and connected to the valve stem 31 through a locking member. The locking member may be a screw or a pin, etc.

[0039] In some examples, the locking member may be eliminated, and an internal thread may be provided on the inner wall of the assembly port, and an external thread may be provided on the end of the valve stem 31, and the valve flap 32 may be fixed to the valve stem 31 by screwing the internal thread and the external thread. In addition, in other examples, the assembly port on the flap body 321 may be eliminated, and the flap body 321 may be directly fixed to the end of the valve stem 31 by a locking member or a clamping structure.

[0040] The abutment portion 322 is disposed at one end of the flap body 321 away from the valve stem 31, and the outer surface of the abutment portion 322 forms the abutment surface of the valve core 30. In some embodiments of the present application, the abutment surface on the abutment portion 322 is an inclined surface, and in the direction in which the valve core 30 extends into the valve body 10, the outer diameter of the abutment portion 322 tends to gradually decrease.

[0041] In addition, in some embodiments of the present application, the valve 100 may further include an elastic tube body, which may be a bellows, and may be made of an aging-resistant and corrosion-resistant elastic material such as polytetrafluoroethylene.

[0042] The elastic tube body is sleeved on the outer circumference of the valve stem 31, one end of the elastic tube body is sealed and connected to the inner side of the valve cover, and the other end of the elastic tube body is sealed and connected to the end surface of the valve flap 32 facing the valve cover. In some examples, the valve 100 may also include a spring, which is sleeved on the outer circumference of the valve stem 31 and accommodated in the elastic tube body, and the two ends of the spring are respectively fixed to the valve cover and the valve flap 32.

[0043] Further, in some embodiments of the present application, a receiving position 13 is provided inside the valve body 10, and the receiving position 13 is provided corresponding to the installation opening 15 of the valve body 10. The receiving position 13 is a groove-shaped structure, which is recessed on the inner wall of the valve body 10.

[0044] When the valve body 10 is processed, such as by casting or forging machining, a groove-shaped accommodation position 13 can be reserved at a set position. The depth of the accommodation position 13 is not less than 4 mm, and the inner diameter of the accommodation position 13 is a negative tolerance, and the tolerance range is -0.05 mm-0 mm.

[0045] The valve 100 further includes a prefabricated ring 20, which is disposed in the accommodating position 13, and the inner wall of the prefabricated ring 20 is formed with a sealing surface 201. The valve core 30 moves relative to the valve body 10, and the valve flap 32 can partially extend into the prefabricated ring 20, and the abutting surface on the abutting portion 322 can abut against the sealing surface 201 of the prefabricated ring 20 to form a seal.

[0046] In some embodiments of the present application, the sealing surface 201 of the prefabricated ring 20 is an inclined surface, and the inner diameter of the prefabricated ring 20 tends to gradually decrease in the direction in which the valve core 30 extends into the valve body 10 .

[0047] This arrangement can be adapted to the abutment portion 322 on the valve core 30 whose outer diameter is gradually decreasing, so that the abutment surface and the sealing surface 201 form an effective sealing fit, thereby ensuring the sealing performance of the cooperation between the two.

[0048] In some examples, the prefabricated ring 20 may include a ring base 21 and a ring body 22 that are annular and connected, and the outer surfaces of the ring base 21 and the ring body 22 are flush. The ring body 22 is arranged on the side of the ring base 21 facing the installation port 15, and the inner wall of the ring body 22 constitutes a sealing surface 201, and the inner wall of the ring base 21 and the sealing surface 201 are arranged at an obtuse angle.

[0049] When the end of the valve core 30 extends into the prefabricated ring 20, the abutting portion 322 of the valve flap 32 first contacts the ring body 22 of the prefabricated ring 20, and the abutting surface of the abutting portion 322 slides against the sealing surface 201 of the ring body 22 until the two abut and abut to form a seal. When the abutting surface forms a seal with the sealing surface 201, the outer end of the valve flap 32 can abut against the connection between the ring base 21 and the ring body 22, that is, the connection between the ring base 21 and the ring body 22 provides a limit to the movement stroke of the valve core 30.

[0050] In some embodiments of the present application, the prefabricated ring 20 is a prefabricated alloy part, and the prefabricated ring 20 is cast from cemented carbide powder to ensure the hardness and wear resistance of the prefabricated ring 20, thereby effectively ensuring the sealing of the valve core 30 and the valve body 10.

[0051] In some examples, the cemented carbide powder used to make the preformed ring 20 can be a cobalt-based alloy, which includes the following components by weight percentage: Co: 44.5%-65.1%, C: 0.9%-1.4%, Cr: 28%-30%, Fe: 0.8%-3%, Mo: 0.2%-1%, Ni: 0.8%-3%, Si: 0.7%-1.55%, and W: 3.5%-5.5%.

[0052] In other examples, the prefabricated ring 20 may also be made of other materials with good hardness and wear resistance, which are not limited too much here, as long as the prefabricated ring 20 can meet the actual use requirements.

[0053] In some embodiments of the present application, the prefabricated ring 20 can be made by casting, and the thickness of the prefabricated ring 20 at the sealing surface 201 is not less than 1 mm, and the hardness of the prefabricated ring 20 is 38HRC-45HRC. In order to ensure the effective fixation of the prefabricated ring 20 at the accommodating position 13, the outer diameter of the prefabricated ring 20 is a positive tolerance, and the tolerance range is 0mm-0.05mm, so that when the prefabricated ring 20 is placed in the accommodating position 13, the prefabricated ring 20 can be tightly matched with the valve body 10.

[0054] After the prefabricated ring 20 is placed in the receiving position 13, the outer wall of the prefabricated ring 20 and the inner wall of the valve body 10 corresponding to the receiving position 13 are welded and fixed by electron beam welding. Electron beam welding uses an accelerated and focused electron beam 300 to bombard the welding surface between the prefabricated ring 20 and the valve body 10, so that the welded surface is melted to achieve welding.

[0055] The prefabricated ring 20 and the valve body 10 are fusion welded by electron beam welding. The maximum thickness of the weldable prefabricated ring 20 can reach 200 mm, the weld width can be no more than 1 mm, and the heat affected zone is extremely narrow, which can effectively solve the problems of welding connection causing the welding fusion zone to lose its fine microstructure, unable to achieve optimal toughness, and reduced wear resistance due to carbide decarburization.

[0056] Furthermore, vacuum electron beam welding is used to weld the prefabricated ring 20 and the valve body 10 , which has high welding quality and can ensure high connection strength, thereby effectively improving the stability of the overall structure of the valve body 10 .

[0057] In addition, in view of the difficulty that the welding gun of the prior art cladding equipment cannot weld the valve 100 with a smaller nominal diameter, the technical solution of the present application adopts a prefabricated ring 20 to form the sealing surface 201, and combines electron beam welding to perform fusion welding between the prefabricated ring 20 and the valve body 10, which can be effectively applied to the formation of the sealing structure in the valve 100 with a smaller nominal diameter, especially the sealing structure of the valve 100 with a diameter less than DN40, an aperture less than 30mm, and a depth greater than 50mm.

[0058] See also Figure 4 In one embodiment of the present application, there is also provided a method for manufacturing a valve 100, which can manufacture the valve 100 of the above structure. The manufacturing method comprises the following steps: S10: processing the valve body 10, forming a connected inlet 11 and an outlet 12 on the valve body 10, and forming a receiving position 13 inside the valve body 10; S20: processing the prefabricated ring 20, the size of the prefabricated ring 20 can be adapted to the size of the accommodation position 13, and assembling the prefabricated ring 20 to the accommodation position 13, so that the valve body 10 and the prefabricated ring 20 form an assembly structure; S30: welding the assembled structure by electron beam welding, so that the outer wall of the prefabricated ring 20 is welded and fixed to the inner wall of the valve body 10 corresponding to the accommodating position 13; S40: A sealing surface 201 is processed on the inner wall of the prefabricated ring 20. The sealing surface 201 can abut against the abutting surface at the end of the valve core 30 to form a seal.

[0059] In step S10, when the valve body 10 is processed, such as when the valve body 10 is manufactured by casting or forging machining, a groove-shaped accommodation position 13 can be reserved at a set position. The depth of the accommodation position 13 is not less than 4 mm, and the inner diameter of the accommodation position 13 is a negative tolerance, and the tolerance range is -0.05 mm-0 mm.

[0060] When the valve body 10 is processed, a flow channel 14 is formed inside the valve body 10 , an inlet 11 and an outlet 12 are formed at both ends of the valve body 10 , and a mounting port 15 is formed on the side of the valve body 10 .

[0061] In step S20, the prefabricated ring 20 is cast from cemented carbide powder to ensure the hardness and wear resistance of the prefabricated ring 20, thereby effectively ensuring the sealing of the valve core 30 and the valve body 10. The hardness of the prefabricated ring 20 is 38HRC-45HRC.

[0062] The cemented carbide powder used to make the preformed ring 20 can be a cobalt-based alloy, which includes the following components by weight percentage: Co: 44.5%-65.1%, C: 0.9%-1.4%, Cr: 28%-30%, Fe: 0.8%-3%, Mo: 0.2%-1%, Ni: 0.8%-3%, Si: 0.7%-1.55%, and W: 3.5%-5.5%.

[0063] In other examples, the prefabricated ring 20 may also be made of other materials with good hardness and wear resistance, which are not limited too much here, as long as the prefabricated ring 20 can meet the actual use requirements.

[0064] After the prefabricated ring 20 is cast and passed the flaw detection, it is processed according to the size of the receiving position 13 in the valve body 10. The outer diameter of the prefabricated ring 20 is a positive tolerance, and the tolerance range is 0mm-0.05mm. This ensures that when the prefabricated ring 20 is placed in the receiving position 13, the prefabricated ring 20 can be tightly matched with the valve body 10.

[0065] After the prefabricated ring 20 is processed, the prefabricated ring 20 can be first frozen by ice water or liquid nitrogen, and then the frozen prefabricated ring 20 is placed in the accommodating position 13, so that the valve body 10 and the prefabricated ring 20 form an assembled structure.

[0066] When the prefabricated ring 20 and the valve body 10 are assembled, they can be pressed in appropriately to ensure that the prefabricated ring 20 is in close contact with the inner wall of the accommodating position 13 of the valve body 10 without any obvious gap.

[0067] Combination Figure 5 In step S30, after the prefabricated ring 20 and the valve body 10 are assembled, after the assembled structure returns to room temperature, the assembled structure is first placed in a vacuum chamber for high-energy electron beam welding, and the vacuum chamber is evacuated to a vacuum degree below 0.01 Pa.

[0068] Then, electron beam welding is used to weld with extremely fine high-energy electrons. The electron beam welding device is placed on the outside of the valve body 10, and then the outer wall of the prefabricated ring 20 and the inner wall of the corresponding accommodating position 13 of the valve body 10 are heated and melted by the electron beam 300 through the installation opening 15 of the valve body 10 along the inner wall of the accommodating position 13 of the valve body 10, so that the prefabricated ring 20 and the valve body 10 are welded into one.

[0069] The prefabricated ring 20 and the valve body 10 are fusion welded by electron beam welding. The maximum thickness of the weldable prefabricated ring 20 can reach 200 mm, the weld width can be no more than 1 mm, and the heat affected zone is extremely narrow, which can effectively solve the problems of welding connection causing the welding fusion zone to lose its fine microstructure, unable to achieve optimal toughness, and reduced wear resistance due to carbide decarburization.

[0070] Furthermore, vacuum electron beam welding is used to weld the prefabricated ring 20 and the valve body 10 , which has high welding quality and can ensure high connection strength, thereby effectively improving the stability of the overall structure of the valve body 10 .

[0071] In addition, in view of the difficulty that the welding gun of the prior art cladding equipment cannot weld the valve 100 with a smaller nominal diameter, the technical solution of the present application adopts a prefabricated ring 20 to form the sealing surface 201, and combines electron beam welding to perform fusion welding between the prefabricated ring 20 and the valve body 10, which can be effectively applied to the formation of the sealing structure in the valve 100 with a smaller nominal diameter, especially the sealing structure of the valve 100 with a diameter less than DN40, an aperture less than 30mm, and a depth greater than 50mm.

[0072] Combination Figure 6 For step S40, after the prefabricated ring 20 and the valve body 10 are welded, a sealing surface 201 is machined on the inner wall of the prefabricated ring 20 according to the size requirements by mechanical grinding. The sealing surface 201 is used to abut against the abutting surface of the end of the valve core 30 to form a seal.

[0073] The processing step of the sealing surface 201 on the prefabricated ring 20 is located after the step of welding the prefabricated ring 20 and the valve body 10. This setting can avoid the deformation of the sealing surface 201 caused by high temperature and high heat in the welding operation, and can effectively ensure the accuracy of the sealing surface 201 in the prefabricated ring 20.

[0074] The thickness of the processed prefabricated ring 20 at the sealing surface 201 is not less than 1 mm, and the hardness of the prefabricated ring 20 at the sealing surface 201 is 38HRC-45HRC.

[0075] In addition, for other components in the valve 100, such as the valve cover, valve stem 31, elastic tube body, spring, etc., after completing step S40, the valve cover, valve stem 31, elastic tube body, spring, etc. can be assembled on the valve body 10 according to the assembly order of each component, thereby completing the production of the valve 100.

[0076] For the valve and manufacturing method of the present application, the valve includes a valve body, a prefabricated ring and a valve core, the inner wall of the prefabricated ring is formed with a sealing surface that abuts against the abutting surface on the valve core, and the valve core can abut against the sealing surface of the prefabricated ring to achieve sealing inside the valve body. The sealing surface is formed on the prefabricated ring, and the assembly of the prefabricated ring in the valve body is realized by electron beam welding, which can effectively solve the problem that the welding gun cannot enter the internal space of a smaller size for surfacing and cannot form a reliable quality sealing surface, thereby ensuring that the sealing surface of the valve can meet the requirements of higher hardness and wear resistance, and effectively improve the overall stability and reliability of the valve.

[0077] Although the present invention has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present invention can be embodied in a variety of forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A method for manufacturing a valve, characterized in that: The steps include: Processing the valve body, forming a connected inlet and outlet on the valve body, and forming a receiving position inside the valve body; Processing a prefabricated ring, the size of which can be adapted to the size of the accommodation position, assembling the prefabricated ring to the accommodation position, so that the valve body and the prefabricated ring form an assembly structure; The assembly structure is welded by electron beam welding so that the outer wall of the prefabricated ring is welded and fixed to the inner wall of the valve body corresponding to the accommodation position; A sealing surface is then processed on the inner wall of the prefabricated ring, and the sealing surface can abut against the abutting surface at the end of the valve core to form a seal.

2. The method for manufacturing a valve according to claim 1, characterized in that: The accommodating position is a groove-shaped structure, and the depth of the accommodating position is not less than 4 mm; the inner diameter of the accommodating position is a negative tolerance, and the tolerance range is -0.05 mm-0 mm.

3. The method for manufacturing a valve according to claim 1, characterized in that: The prefabricated ring is made of cemented carbide powder by casting, and the cemented carbide powder is made of cobalt-based alloy; The cobalt-based alloy comprises the following components by weight percentage: Co: 44.5%-65.1%, C: 0.9%-1.4%, Cr: 28%-30%, Fe: 0.8%-3%, Mo: 0.2%-1%, Ni: 0.8%-3%, Si: 0.7%-1.55%, W: 3.5%-5.5%; The outer diameter of the prefabricated ring has a positive tolerance, and the tolerance range is 0mm-0.05mm.

4. The method for manufacturing a valve according to claim 1, characterized in that: After the processing of the prefabricated ring is completed, before the prefabricated ring is assembled with the valve body, the prefabricated ring is first frozen, and then the frozen prefabricated ring is assembled to the receiving position to generate an interference fit between the prefabricated ring and the valve body.

5. The method for manufacturing a valve according to claim 1, characterized in that: Before welding the assembled structure by electron beam welding, the assembled structure is first placed in a vacuum chamber for vacuum treatment so that the vacuum degree is not greater than 0.01Pa.

6. The method for manufacturing a valve according to claim 1, characterized in that: The thickness of the prefabricated ring at the sealing surface is not less than 1 mm, and the hardness of the prefabricated ring at the sealing surface is 38HRC-45HRC.

7. A valve, characterized in that: The valve is manufactured by the manufacturing method according to any one of claims 1 to 6, and the valve comprises: A valve body is provided with an inlet and an outlet connected to each other, and a receiving position is provided inside the valve body; A prefabricated ring, arranged in the accommodation position, wherein the inner wall of the prefabricated ring is formed with a sealing surface; The valve core is movably arranged on the valve body, and the end of the valve core can extend into the interior of the valve body, and the end of the valve core is formed with an abutment surface; the valve core moves relative to the valve body so that the end of the valve core can extend into the prefabricated ring and the abutment surface abuts against the sealing surface to form a seal.

8. The valve according to claim 7, characterized in that The sealing surface is an inclined surface, and in the direction in which the valve core extends into the valve body, the inner diameter of the prefabricated ring tends to gradually decrease; The abutting surface is an inclined surface, and in the direction in which the valve core extends into the valve body, the outer diameter of the end portion of the valve core where the abutting surface is formed tends to gradually decrease.

9. The valve according to claim 8, characterized in that The prefabricated ring comprises a ring base and a ring body which are both annular and connected, the outer surfaces of the ring base and the ring body are flush; the inner wall of the ring body constitutes the sealing surface, and the inner wall of the ring base and the sealing surface are arranged at an obtuse angle.

10. The valve according to claim 7, characterized in that The accommodation position is a groove-shaped structure opened inside the valve body, and the outer wall of the prefabricated ring and the inner wall of the valve body corresponding to the accommodation position are welded and fixed by electron beam welding.

11. The valve according to claim 7, characterized in that The prefabricated ring is a prefabricated alloy part, and the prefabricated ring is cast from cemented carbide powder.

12. The valve according to claim 11, characterized in that The cemented carbide powder is a cobalt-based alloy, and the cobalt-based alloy includes the following components by weight percentage: Co: 44.5%-65.1%, C: 0.9%-1.4%, Cr: 28%-30%, Fe: 0.8%-3%, Mo: 0.2%-1%, Ni: 0.8%-3%, Si: 0.7%-1.55%, W: 3.5%-5.5%.

13. The valve according to claim 7, characterized in that The valve also includes a valve cover, which is arranged on the valve body and has a mounting hole. The valve core includes a valve stem and a valve flap connected to the end of the valve stem, and the end of the valve stem away from the valve flap is movably inserted into the mounting hole of the valve cover. The end surface of the valve flap away from the valve stem is formed with the abutment surface.

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